郎尼根談潛能與限制，一方面傳承了亞里士多德和多瑪斯的論點，另一方面又觸及當今科學所提示的「能量」，以致讓我們瞥見郎氏形上學的博古通今。昔者，亞里士多德和多瑪斯談「形質論」與「潛能與現實說」，朗尼根進一步把其中的論點加以統合，並藉「三合一」方式把「認知結構」的「經驗、理解、判斷」來對應「存有結構」的「潛能、形式、實現」，並強調「質料」的「潛能」之為「限制原理」。限制著「形式」與「實現」的走向，恰如「經驗」制約著「理解」和「判斷」的活動一般。再者，亞氏和多瑪斯以「元質／Prime Matter」作為物理存有者的究極底線，郎尼根則代之以「原初潛能／Prime Potency」一辭來談宇宙萬物的究極底線，藉此掀起了「存有」以「能量／Energy」作為「限制原理」的討論，並提示「能」聯繫著存有者的「有」。

With regard to the thesis on potency and limitation, Lonergan manages to connect the Scholastic metaphysical viewpoint with the contemporary scientific hypothesis concerning energy. The Aristolelian - Thomistic theories on ＂hylomorphism＂ and ＂potency and act＂ are taken over by Lonergan who synthesizes the ontological structure of being in a triple – pattern of ＂potency-form-act＂ in harmony with the threefold pattern of ＂experience-understanding-judgment＂ within the cognitional structure. He introduces the new term ＂prime potency＂ by comparing it with the Scholastic concept of ＂prime matter＂, attempting to modernize the classical term in the light of the contemporary scientific theory of energy. As a principle of limitation, potency conditions the being of form and act in an isomorphic manner analogical to experience conditioning understanding and affirmation in our way to knowledge.